In a series regulator, what is the purpose of fold-back limiting?

• A. to provide more current in the case of a short circuit
• B. to limit output voltage if input voltage goes too high
• C. to bypass the pass-transistor, if the pass-transistor should fail
• D. to provide current up to a maximum, but drop current to a lower value when the output becomes shorted, to prevent overheating of the device